William a



W. A. DUCKBR.

Parallel Ruler.

Patented oct. 26, 1880.

N.PETERS, PHOTULITHDGRAFHER. WASHINGTON. D C.

y UNITED STATES VILLIAM A. DUOKEB, OF BURGOYNE, ONTARIO, CANADA.

PARALLEL RULER.

SPECIEICAIIONy forming part of Letters Patent No. 233,737, dated October 26, 1880.

Application filed January 24, 1880.

To all 'whom t may concern:

Be it known that I, WILLIAM A. DUGKER, of Burgoyne, Bruce county, Province of Ontario, Canada, have invented a new and Improved Parallel Ruler, of which the following is a specification.

Figure l is a view showing the upper side of the device. Fig. 2 is a section on line x x, Fig. 1. Fig. 3 is an end elevation of the device. Fig. 4 is a rear elevation of the device.

Similar letters of reference indicate corresponding parts.

The object of this invention is to provide a simple and cheap parallel ruler, by which all parallel ruling, and especially shading and section-lining, can be quickly and accurately performed. v

The invention consists of a fiat plate, of wood or other suitable material, attached to a revolving rod, on which are fixed milled rollers; and there isalso a mechanism for moving the device and regulating the width of the spaces between the lines drawn, with certain other novel parts, hereinafter described.

In the drawings, A represents the plate of the ruler; B, the milled wheels, rigidly attached to the rod D, which is connected to the plate A by the pieces C, in which the rod D can freely turn.

The shifting mechanism consists ofthe iixed screw E, on which revolves the milled head F, the sliding piece J, with knob L, and crosshead K, the guides N, and the stops O. Under the shifting piece J is the spring M, (shown by dot-ted lines, Fig. 1) to keep J from contact with the roller B when J is not pressed down. There is also a pad, P, of rubber or other suitable material, attached to the under side of J, as shown in Fig. 2.

To operate the device the piece J is slid up till the cross-head K comes in contact with the fixed stops 0, and the milled head F is turned as far from K as it is desired to place the lines apart. The edge of the plate A is then placed where it is required to draw the first line, and that line is drawn. Then the piece J is slid down till its cross-head Kcomes in contact with the milled head F. The piece J is then pressed down till the pad P comes in contact with the milled roller B, and in this position it is drawn backward till the cross-head K comes in contact with the fixed stops O andis stopped by them. This operation causes the rollers B to revolve and carry the plate A to the proper position for the second line, which is then drawn, and this operation is repeated for each subsequent line.

lf it is required to gradually increase or diminish the spacing the milled head F may be turned a part of a revolution or more for each line drawn, thus increasing or diminishing the spaces gradually and evenly as much as the operator may choose.

Instead of the pad P being attached to J, it may be attached to the center roller, B, (which will then be made of a correspondin gly-smaller diameter,) in the shape of a band, and the piece J ribbed or provided with other suitable projections to come in contact with B to insure its revolving.

The plate A may extend to any convenient distance beyond the end rollers, B, and in long rulers there may be four rollers independent of the center one, to enable ruling to be done on surfaces narrower than the length of the ruler.

The edge of the plate A may be graduated to any convenient scale, and on its upper part may be scales of chords, tangents, &c.

Curves or other patterns may be attached to the edge of the plate A, so as to move with it for the purpose of duplicating designs.

l claim as new and desire to secure by Letters Patent- 1. The combination of the plate A, rollers B, shaft D; pieces C, for attaching the shaft and rollers to the plate A, with the shifting mechanism consisting of the fixed screw E, the milled head F, the sliding piece J, with nut L, cross-head K, and part M, the guides N, and the stops O, constructed and arranged substantially as herein shown and described.

2. The shifting mechanism consisting ofthe fixed screw E, the milled head F, the sliding piece J, with its knob L and cross-head K, the pad P, and the spring M, substantially as and for the purpose described.

3. The application of the pad P to the milled roller B, (the pad being changeable from the piece J to the roller 13,) substantially as and for the purpose herein described.

4. The arrangement of the milled head F on the fixed screw E, in combination with the sliding piece J and fixed stops O, substantially as and for the purpose herein described.

5. The sliding piece J, with its knob L and cross-head K, in combination with the pad P, the spring M, guides N, stops O, screw E, 1o and milled head F, substantially as lund for the purpose herein described.

WILLIAM A. DUGKER. Witnesses:

GYRUs CARROLL, J onN A. FORBES. 

